1. Auxiliary Views

2. Views Refresher
Three views are usually all that are needed to illustrate simple objects
Top
Front
Right
Sometimes only two views are necessary
Cylinders

3. What’s a problem with these views when you’re working with circles?
A circle will look like an ellipse in the top, front, or right side view.

4. Sometimes, the principal views do not work…
One example is when there is a circle or an inclined plane or some other special type of feature of the object.
Sometimes, we just need to show an object at an odd angle because there is something very specialized about the object that cannot be seen from the front, top or right side views.

5. Auxiliary View
A very special orthographic view that projects on any plane that is not one of the size primary views (front, back, top, bottom, left or right sides)
Perpendicular to the inclined part of the object
Circles really look like circles
The true length, true width, true depth, and true shape is shown

6. Why would we want to add another view?
We needed to show the true length of a line or a part or the point of view of some part of an object or edge
We needed to show the true shape and size of part of an object
We have a circle and need to draw the circle first to get the front or side or top view (sometimes called reverse construction)

7. The auxiliary view is parallel to the inclined surface and shows the true size and shape.

8. Steps to Draw Primary Projections:

9. Steps to Draw Auxiliary View:

10. Reference Planes A reference plane is like the glass box projection
It is the edge of the related view
For example, if the reference plane is the front view, the auxiliary view will be projected out parallel from the inclined part as seen from the front view.
Consider this, the reference plan is the edge in the auxiliary view.

11. View Classification
An auxiliary view can be positioned anywhere around an object as the engineering designer chooses.
It is possible to then create additional auxiliary views from the auxiliary view.

12. View Classification These are classified as:
Primary – the first auxiliary view projected from one of the six principal views (top, front, sides, back, bottom)
Secondary – A single view projected from a primary auxiliary view
Tertiary – a single view projected from a secondary or another tertiary auxiliary view

13. Primary Auxiliary Views
Primary Auxiliary Views are also defined by the dimension that is shown in the true size
Depth – projected from the front view and the depth dimension is the true length
Height – projected from the top view and the height dimension is the true length
Width – projected from the side view and the width dimension is the true length

14. Primary Views & Primary, Secondary, & Tertiary Auxiliary Views
Depth (front), Height (top) & Width (side) Auxiliary Views
Are there any questions about these different views before we go forward?

15. Auxiliary Views Let’s make it easier on the engineering designer.
If there is a hidden part or something that is not inclined, we do not place it in an auxiliary view usually.
Also, we often only show the inclined part of the object which is called a partial auxiliary view.
This saves time and effort and is easier to view on a working drawing.
If the object is completely symmetrical, only half of the inclined part is drawn. This is called a half auxiliary.

16. Drawing a Primary Auxiliary View

17. Red construction lines are projected perpendicular to the inclined plane

18. Red construction lines are projected for the right and side views

19. Circle where the projected angle construction line crosses the top and side views. Draw a line connecting the two points. Then, draw a parallel line.

20. Draw arcs of the same radius and then draw lines parallel to front view

21. You can see how the true size and shape of the circle shows in the auxiliary view

22. Clean it up. No construction or projection lines. Dimension correctly.

23. Now you can see why a partial auxiliary primary view is better…

24. Reminder….
An auxiliary view is simply another view that shows something like true size and true shape that the principal views like top, front, and right side can not show.